Well, the problem is that you don't have the menu in the backend. So you will have to manually type in the url
index.php?option=com_hotspots and that is lame.
I don't know why this happens, but what I've found to be a way to fix it is to go to phpmyadmin
go to the extensions table - find hotspots - remove all entries of it, then go to the menu table remove all entries of hotspots and finally the assets table -> remove all entries from there as well and it the installation after that normally doesn't create problems.
But why that brakes in the first place is still a mystery for me...
Cheers,
Daniel